feat: Implement Telegram alerts for catalog updates and failures

test/support/nextcloud.js

@@ -1,4 +1,5 @@
 import { createServer } from "node:http";
+import { createHash } from "node:crypto";
 import { readFileSync, mkdtempSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
@@ -22,6 +23,12 @@ const files = {
   [`${FOLDER}Медленный.docx`]: "slow",
 };
 const folders = [SHARE, `${SHARE}${YEAR}/`, `${SHARE}${YEAR}/Финансово-экономический факультет/`, FOLDER];
+// Dates of files changed during a test; the others keep MODIFIED.
+const dates = {};
+const dateOf = (path) => dates[path] || MODIFIED;
+// As in Nextcloud, a folder's ETag changes whenever anything below it does.
+const etagOf = (folder) =>
+  `"${createHash("sha1").update(Object.keys(files).filter((f) => f.startsWith(folder)).sort().map((f) => f + dateOf(f)).join("|")).digest("hex").slice(0, 13)}"`;
 
 const encode = (path) => path.split("/").map(encodeURIComponent).join("/");
 const listing = (folder) => {
@@ -32,19 +39,23 @@ const listing = (folder) => {
     const size = Buffer.isBuffer(files[path]) ? files[path].length : 1000;
     return `<d:response><d:href>${encode(path)}</d:href><d:propstat><d:prop>${
       folder ? "<d:resourcetype><d:collection/></d:resourcetype>" : `<d:resourcetype/><d:getcontentlength>${size}</d:getcontentlength>`
-    }<d:getlastmodified>${MODIFIED}</d:getlastmodified></d:prop><d:status>HTTP/1.1 200 OK</d:status></d:propstat></d:response>`;
+    }<d:getlastmodified>${dateOf(path)}</d:getlastmodified><d:getetag>${folder ? etagOf(path) : `"${dateOf(path)}"`}</d:getetag></d:prop><d:status>HTTP/1.1 200 OK</d:status></d:propstat></d:response>`;
   };
   return `<?xml version="1.0"?><d:multistatus xmlns:d="DAV:">${[folder, ...children].map(entry).join("")}</d:multistatus>`;
 };
 
 /**
  * Starts the stand-in and the API server; `env` adds settings such as lower limits.
- * Returns the server's base URL, request statistics of the stand-in and `stop()`.
+ * Returns the server's base URL, request statistics of the stand-in, `catalog` to change the
+ * stand-in's documents during a test, and `stop()`.
  */
 export async function startApi(env = {}) {
-  const stats = { requests: 0, connections: 0 };
+  const stats = { requests: 0, connections: 0, listings: 0 };
+  let down = false;
   const source = createServer((req, res) => {
     stats.requests++;
+    if (req.method === "PROPFIND") stats.listings++;
+    if (down) return res.writeHead(503).end();
     const path = decodeURIComponent(req.url);
     if (req.method === "PROPFIND" && folders.includes(path)) {
       res.writeHead(207, { "Content-Type": "application/xml" });
@@ -67,9 +78,22 @@ export async function startApi(env = {}) {
   const { app } = await import("../../server/index.js");
   const server = app.listen(0, "127.0.0.1");
   await new Promise((resolve) => server.on("listening", resolve));
+  let tick = 0;
   return {
     base: `http://127.0.0.1:${server.address().port}`,
     stats,
+    catalog: {
+      /** Publishes a document in the faculty folder (or republishes it) with a new date. */
+      put(name, body) {
+        const path = FOLDER + name;
+        files[path] = body;
+        dates[path] = new Date(Date.parse(MODIFIED) + ++tick * 60_000).toUTCString();
+      },
+      /** The university stops (true) or starts again (false) answering. */
+      down(on) {
+        down = on;
+      },
+    },
     stop() {
       server.close();
       server.closeAllConnections();